Platform or base rocker.



Patented Feb. l2, |901.

w. l. BUNKER.

PLATFORM 0B BASE maken.

(Application filed Jan. 29, 1900.)

(No Model.)

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i'I/IILLIAM I. BUNKER, OF LA GRANGE, ILLINOIS.

PLATFORM @Pi Blih HUUIEI.

forming; part of Letters Patent No. 667,967, dated. February 12, 1901.

Application filed January 29, 1900. ncrial No. 5,148. alle model.)

To {zt/Z 1072/0111/ it 'ln/(ty coll/cern,

it known that I, WLLIAM I. BUNKER, a citizen of the United States,residing at La Grange, in the county of Cook and State of Illinois, haveinvented a new and useful Improvement in Platform or Base Rockers, ofwhich the followiiur is a specification.

Platform or base rockers in order to be comfoi-table should have thesame easy rolling or rocking movement found in floor-rockers, andnumerous attempts have been made to secure this result in theconstruction of platform or base rochers by the employment of springs ofvarying' construction and arrangement, but without attaining.;lpractically a rocher of the platform or base type with an easy andregular rocking movement.

rihe object of my invention is to construct a platform or base rockerhaving therein the rolling or rocking' movimient of an ordinaryflow-roche Iand without any of the objectionable features found wheresprings are employed to secure a roekiugj` movement; and the inventionconsists in the features of construction and combination of partshereinafter described and claimed,

ln the drawings illustrating my improve ment, Figure l is a sideelevation showing,r the seni' and body of the chair and the rolling orrocking contacts or bearings on which the parts are supported in normalposition; Fig. 2, aside elevation showing the parte in the positiontheaoccupy when the chair is rocked or lipped backward; Fie'. 3, a frontelevation with theI baci; of he chair-body broken away, showin;r theparte in the position of Fig. l; Fig. l, adel ail in lonnit udinalsection through the side rail of the base and the side rail of theseat-frame with the rolling contacts or bearings in elevation, and Fig'.5 a detail in section taken on line of Fig. e.

In carrying` out my invention in one form of construction I provide abase having side rails or heads A, united by a cross-piece Al. Each siderail or head is inclined from its central point downward on each side,so as to 'forni a contact or bearing face a, and each bearing-face hastherein a groove or race d', furnishing traveling-surface The seatframeis provided on each side with atrail or head B to aline with itscompanion rail or head A of the bane, and in the form shown each siderail or head of the frame is of a concave shape on its` under side,forming on each side of its center a contact or bearing` face I), andeach bearing-face has therein a groove or race ZJ, forming atraveling-surface to coact with the travoling-surfaee of the base railor head. The grooves or races in the side rails or heads are located oneach side of the center of motion of theehair, and between the siderails or heads in each groove or race is located or interposed betweenthe two parts composing the chair rocking or rolling` contacts orbearings on which the frame of the chair and the body C thereof aresupported and travel. The preferred form of rolling;` contact orbearing' is in the shape of a round ball c, preferably of rubber, andfor use willi such form of rolling contact or bearing,r the grooves orraces have a shape in cross-section to lit the exterior of the ball, asshown in Fig. 5. Instead of a rolling contact or bearing` in the shapeof a ball such contact or bearing may be of a cylindrical form and inthe shape of a solid body or a tube, and its bearingface maybe plain orstraight or otherwise formed so long' as the surface presented is onewhich will give the required support and roll or roel; for the easytravel of the body in its rocking movements, and instead of rubberldiese rolling,r contacts or bearings may be of wood, metal, or othermaterial suitable for the purpose. It will be understood that the grooveor race to conform as to shape in cross-section with the form of theexterior face of the rollingr contact or bearing.

The preferred shape of the bottom or bearing' face of the groove or racea' is shown in Fig. 5, as is also the preferred form of the bottom orbearing face of the `:groove or race b. It will be noticed that when theparts are in normal position the race formed is farthest apart at thecenter and nearest together at the ends, giving' a concave ordish-Shaped bearing-'face loi'igitudinally for both the base and chairon each side of the center of motion. This form of construction for therace gives the required traveling-surface for the rolling contacts orbeari ngs, by which an easy movement is had in rocking, as the contactsor bearin roll to and fro between the Contact or bearingr faces of theside rails or heads.

The chair-body may be connected With its IOO basein any suitable manner.As shown, such connection is furnished by a spring CZ, one end of whichis connected with a bracket e, secured to the side rail or head of theseatframe,and the other end of which is connected with a bracket f,secured to the side rail or head of the base, and a springis providedfor each side of the chair. These springs do notv in any manner controlthe rocking movement, which is controlled solely and wholly by thetravel of the rolling contacts or bearings. The springs are merely forthe purpose of holding the chair-body to the base, and instead ofcoil-springs rubber straps or other form of connection can be appliedand used for the purpose, so long as the connection is one that willpermit of perfect flexibility between the parts of the chair for therocking or rolling movement.

The rolling or rocking contacts or bearings furnish a traveling supportbetween the base side rails or heads and the frame side rails or heads,on which the chair-body is mounted and carried and by which a perfectlyfree and easy rocking movement is secured, and such movement is had fromthe travel of the rolling contacts or bearings on the travelingsurfacesfurnished by the grooves or racesin which they are located and theconformation of sn'ch grooves or races, by which an easy gradual rock isproduced without any jerk, jar, or connection.

I claiml. In a platform or base rocker, the combination of a base and aseat separated from each other and each having an elongatedbearing-face, with the two bearing-faces in vertical alinement andhaving an upward inclination in the direction of the center of motion ofthe seat to the base, and roller-bearings located between and held inplace by engaging the bearing-faces of the base and seat and having anopposite travel on the bearingfaces .in relation to each other towardand from the center of motion, substantially as described.

2. The combination in a rocker, of a base having on its upper surface abearing-face, a seat having on its under surface a bearingface, the twobearing-faces being in vertical alinelnent with each other and eachhaving an upward inclination in the direction of the center of motion ofthe seat to the base, and rolling bearings interposed between thebearing-faces and held in place by the action of such faces between thetwo parts of the chair and having an opposite travel in relation'to eachother toward and from the center of motion permitting the seat to rockbackward and forward, substantially as described.

3. In a platform or base rocker, a frame and base both provided on eachside of the center of motion with a depressed bearing-face, each facehaving an upward inclination in the direction of the center of motion ofthe seat to the base, in combination with a rolling contact or bearingon each side of the center of motion interposed between and common tothe two opposite faces and held in place by the engagement of the faces,the contacts or bearings having an opposite travel in relation to eachother toward and from the center of motion andfurn'ishing a'support forand on which the seat rocks, substantially as described.

4. In a platform or base rocker, the combination of a base having siderails or heads, each provided with inclined supporting-faces and eachface having a retaining and traveling groove, a rocker-frame having siderails or heads, each provided with inclined supporting-faces and eachface having a retaining and traveling groove, and an interposed rollingcontact or bearing traveling in the grooves between the rails or headson each side of the center of motion and held in place by engagementwith the faces of the grooves, substantially as described.

5. In a chair, the combination of a rocker and a base having theiradjacent faces in vertical alinement and separated from each other andeach face having an upward inclination in the direction of the center ofmotion of the seat to the base, individual carriers on each side of thecenter of motion interposed between and in direct contact with t-hefaces on both the rocker and the baseand held in place thereby,eachcarrierhaving an opposite travel in relation one to the other toward andfrom the center of motion, and means for controlling the motion of therocker on the base, substantially as described.

6. In a chair, the combination of a rocker and a base, having theiradjacent faces in vertical alinement and of an elongated dish shape. andseparated from each other, each face having an upward inclination in thedirection of the center of motion of the seat to the base, individualcarriers on each side of the center of motion interposed between and indirect contact with the elongated dish-shaped faces of both the rockerand base, each carrier having an opposite travel one to the other towardand from the center of motion, and means for controlling the motion ofthe rocker on the base, substantially as described.

WILLIAM I. BUNKER.

Witnesses:

BELLE W. BARRY, EPHRAIM BANNING.

